1. Field of the Invention
The present invention relates to a ratchet mechanism, and more particularly to a ratchet mechanism for a screw driver or a wrench.
2. Description of the Prior Art
Two typical ratchet mechanisms are disclosed in U.S. Pat. No. 593,157 to Furbish, and U.S. Pat. No. 5,687,820 to Lin, and comprise a ratchet gear rotatably received in a body, and a pair of pawls biased to engage with the ratchet gear. The ratchet mechanisms comprise an actuator for disengaging either or both of the pawls from the ratchet gear and for controlling the driving directions of the tool. However, the actuator may not be used for effectively actuating the pawls to engage with the ratchet gear.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional ratchet mechanisms.